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| author | Christoph Hellwig <hch@lst.de> | 2019-10-28 13:10:38 +0100 |
|---|---|---|
| committer | Paul Walmsley <paul.walmsley@sifive.com> | 2019-11-17 15:17:39 -0800 |
| commit | fcdc65375186a5cd69cc2eedfb498b86f4f5a21e (patch) | |
| tree | e5f23c3934dc954ff361e672af761365d37edc49 /arch/riscv/kernel/smpboot.c | |
| parent | 4f9bbcefa142862782275a4b29f390ca8d8b9242 (diff) | |
| download | linux-fcdc65375186a5cd69cc2eedfb498b86f4f5a21e.tar.bz2 | |
riscv: provide native clint access for M-mode
RISC-V has the concept of a cpu level interrupt controller. The
interface for it is split between a standardized part that is exposed
as bits in the mstatus/sstatus register and the mie/mip/sie/sip
CRS. But the bit to actually trigger IPIs is not standardized and
just mentioned as implementable using MMIO.
Add support for IPIs using MMIO using the SiFive clint layout (which
is also shared by Ariane, Kendryte and the Qemu virt platform).
Additionally the MMIO block also supports the time value and timer
compare registers, so they are also set up using the same OF node.
Support for other layouts should also be relatively easy to add in the
future.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Anup Patel <anup@brainfault.org>
[paul.walmsley@sifive.com: update include guard format; fix checkpatch
issues; minor commit message cleanup]
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
Diffstat (limited to 'arch/riscv/kernel/smpboot.c')
| -rw-r--r-- | arch/riscv/kernel/smpboot.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c index 261f4087cc39..8bc01f0ca73b 100644 --- a/arch/riscv/kernel/smpboot.c +++ b/arch/riscv/kernel/smpboot.c @@ -24,6 +24,7 @@ #include <linux/of.h> #include <linux/sched/task_stack.h> #include <linux/sched/mm.h> +#include <asm/clint.h> #include <asm/irq.h> #include <asm/mmu_context.h> #include <asm/tlbflush.h> @@ -137,6 +138,9 @@ asmlinkage __visible void __init smp_callin(void) { struct mm_struct *mm = &init_mm; + if (!IS_ENABLED(CONFIG_RISCV_SBI)) + clint_clear_ipi(cpuid_to_hartid_map(smp_processor_id())); + /* All kernel threads share the same mm context. */ mmgrab(mm); current->active_mm = mm; |